Explosive



UNITED STATES PATENT OFFICE.

JOHN R. MARDICK, OF NEW YORK, N. Y., ASSIGNOR. TO ELECTRO METALLURGICAL COMPANY, OF NIAGARA FALLS, NEW YORK, A CORPORATION OI WEST VIR- Patented Apr. 6, 1920.

To all whom it may concern:

Application filed December 15, 1917. Serial No. 207,389.

Following are certain illustrative for- Be it known that I, JOHN R. MAIRDICK, a nuke:-

citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Explosives, of which the following is a specification.

This invention relates to certain novel explosive compositions suitable for blasting and other purposes, and containingas essential components one or more normally solid nitro-aromatic bodies having at least three nitro-groups, of which tri-nitrotoluene (T. N. T.) and picric acid are types, associated with an oxidizing agent or agents,

and with ferrosi licon. The ferrosilicon is present in substantial proportions, prefera-bly between the limits of five and fifteen per cent. of the total weight; and the nitro.- aromatic body is resent in suflicient proportion, and in con unction if necessary with certain low melting-point components, preferably liquid or easily liquefiable dinitro bodies, to im art to the composition asv a whole the desired plastic or cohesive character; for this purpose the nitro body should be in excess by weight of the ferrosilicon.

The oxidizing agents used are preferably the nitrates, chlorates and perchlorates of the alkali metals (including ammonium),

or mixtures of these salts at times in conunctlon with nitrates of heavy metals such as lead or barium.

suitable combustible material typified by wood flour or meal; a small 'proportion of calcium carbonate or other suitable substance acting as an anti-acid; and if required. a waterproofing or coating substance, this latter being used more particularly in case hygroscopic salts such as ammonium-nitrate arepresent in the mixture.

A eneral formula for an explosive comsition embodying, my invention is as folows:

. By weight.

Nitro aromatic compound or compounds 15-30% Ferrosilicon 5 -15% Oxidizer -75% Combustible '1- 5% Anti-acid 0- 11175 7 Other components usually present in the mixture comprise any explosive Blasting ewplosives.

Parts by weight. (1) T. N. T. or picric acid 20 Ferrosilicon 82% Q 12 Ammonium nitrate 4. 0 Sodium nitrate l 21.5 Din itrotoluol '3 Wood flour 3 I Calcium carbonate 0.5 (2) T. N. T. or picric acid... 25 Ferrosilicon 82% "7 Potassium perchlorate; 50 Sodium nitrate 1- 12.5 Wood flour -5 Calcium carbonate, 0.5 (3) T. N. T. or picric acid '20. F errosilicon 82% 12 Ammonium perchlorate 35 Sodium nitrate.. 26.5 Dinitrotoluol 3 Wood flour -1 3 Calcium.carbonate 0.5

Torpedo charge.

(4) T. N. T. or picric acid 20 7 Ferrosilicon 82% 10 Lead nitrat'e 40 Ammonium nitrate 15. Sodium 'nitrate 7.5 Dinitrotoluol 3 Wood flour 4 Calcium carbonate 0.5;

Formulae 1-3 are commercial (blasting) capable of being tamped into lace and comparing favorably in their e ect with commercial grades of dynamlte. Formula number 4 is a torpedo explosive WhICh POS- sesses exceptional. striking power b reason of itarelatlvely large content of lea nitrate. ach of the essential components of the erforms a function in the mixture, and t e roportions of the components will 'be vari in practice as may be necessary to the proper erformance of this function, havin in view the specific purpose for which t e explosive is intended.

The nitro-aromatic bodies are normally solid but readily fusible, and are therefore easily compounded witlrthe other ingredi ents, yielding transportable granular plastic or cohesive compositions which are readily tamped into conformity to the bore. Instead of T. N. T. or picric acid I may use other nitro-aromatic bodies havin similar desirable qualities, as for example triand tetranitro-naphthalene, and the tri-nitro cresols. Nitro-aroimitic bodies having less than three nitro-groups are not equivalent to these.

The oxidizer is insutlicicnt proportion to convert any carbon monoxid into carbon dioxid and serves in general to oxidize all poisonous or objectionable gases or compounds, rendering the products of explosion innocuous. In the case of commercial explosives it is also used in suflicient excess to effect oxidation of the paraifined paper,

wrapper usually employed. The Wood flour or other combustible will unite with any otherwise unconsumed excess of the oxidizing component. body is precautionary, guarding against de velopment from any cause of an acid condition in the mixture.

In case a hygroscopic salt such as ammonium nitrate is used I prefer to introduce into the mixture small proportions, say four per cent. or less, of a liquid capable of coating the salt and thereby protecting it from atmospheric moisture. For this purpose 1 may use vaselinc, oils, etc; but I prefer liquid nitro bodies. such for example as the commercial liquid nitro xylenes, o-dinitro benzene, dinitro toluene or the like. These liquid nitro bodies act as deadening agents, and therefore should not be used in excessive proportions.

Ferrosilicon as a reducing agent presents marked advantages over metallic reducers such as aluminum, magnesium, or even silicon itself. Among such advantages are to be mentioned the following (1) lmproved stability of the mixture and freedom from tendency to deteriorate through slow oxidation.

(2) Decreased sensitiveness of the mixture. The mixtures formulated above require a relatively heavy detonator, preferably N0. 7.

(3) Ferrosilicon is readily pulverized to 100 mesh or finer,'yielding a relatively heavy powder. This results in a reduced bulk of the explosive mixture'for a given weight and power.

(l) The iron component of the ferrosilicon is also oxidized, yielding with the silicon a relatively heavy oxid mixture, as compared for example with aluminum, magnesium, or silicon alone. 'In this connection it will be understood that the blow exerted by the solid particles is a material factor in the brisancc' or shattering effect of the explosive. This effect is greatly enhanced by The use of the anti-acid the use of lead nitrate additions, as in formula No. 4, by reason of the heavy oxidation products formed.

The 82; ferrosilicon mentioned in the specific formula may be replaced by higher or lower grades, particularly such as are readily pulverized to 100 mesh or finer. Ferrosilicon containing less than to per cent. of silicon is undesirable.

The higher grades of ferrosilicon merge into the commercial grades of silicon and while I prefer touse forrosilicon by reason of the advantages before set forth, I regard it as Within my invention to substitute silicon therefor; and both silicon and ferrosilicon are intended to be covered by the expression silicon-containing substance employed in certain of the claims.

I claim 1. A plastic explosive containin as es-' sential components a normally solid fusible nitro-aromatic body having at least three nitro-groups, an oxidizer, a plasticizing ingredient, and a silicon-containing substance, said components proportioned to confer 90 plasticity on the composition. I

2. A plastic explosive containing as essential components a normally solid fusible nitro-aromatic body having at least three nitro-groups, an oxidizer, a plasticizing nitro-body, and a silicon-containing substance, said components proportioned to confer plasticity on the composition.

A plastic explosive containing as essential components a normally solid fusible 100 nitro-aromatic body having-at least three nitro-groups, an oxidizer, a plasticizing ingredient, and fcrro-silicon, said components proportioned to confer plasticity on the composition.

4. A plastic explosive containing as essential components a normally solid fusible nitro-aron'iatic body having at least three nitro-groups, an oxidizer, a plasticizing nitro-body, and ferro-silicon, said components 110 proportioned to confer plasticity on the composition.

5. A plastic explosive containin as essential components a normally soli fusible nitro-aromatic'body having at least three 115 nitro-groups, 15-30%; an oxidizer 5075 /0;

a silicon-containing substance 545%; and :1 relatively small proportion of a plasticizing ingredient; said components proportioned to confer plasticity on the composition.

6. A plasticexplosive'containin as es sential components a 'normally so 1d fusible nitro-aron'iatic body having at leastthree nitro-groups. 15-30%; an oxidizer 50-75%; a silicon-containing substance 125 545", and a relatively small proportion of a. plasticizing nitro-body; said components proportioned to confer plasticity on the composition.

7. A plastic explosive containing as es 130 sential components a normally solid fusible nitro-aromatic body having at least three intro-groups, 15-30%; an oxidizer 50-7 5%; ferro-sili'con 53-15%; and a relatively small proportion of a plasticizing ingredient; said con'lponents proportioned to confer plasticity on the composition.

8. A plastic explosive containing as essential components a normally solid fusible ferro-silicon 545%; and 'a relatively small proportion of a plasticizing nitro-body; said components proportioned, to confer plastic-' .ity on the composition:

In testimony'whereof I aflix my signature. I

JOHN R. MARDIOK. 

